The aim of this study was to verify the benefit and efficacy of the coagulation and flocculation treatment, as a physicochemical part in the treatment of industrial wastewater; in this case the effluents from the municipal wastewater treatment plant in the city of Rioja. Since this establishment is expelling its effluents externally, without any kind of treatment or care, it constitutes a high degree of contamination to lands, bodies of water and even to the inhabitants bordering that zone. The study began in the field, with the respective sampling of the direct effluents from the municipal canal, and later proceeded to a stage of laboratory work, where all the experimental parts of the coagulation and flocculation process were carried out, with the help of the jar test team. The initial concentrations of five contaminant parameters of this effluent (pH, turbidity, SST, dissolved oxygen and nitrates) were first determined, then continued by the establishment of optimum speed, coagulant dosage, flocculant, and sedimentation time, to obtain the greatest amount of reduction of the aforementioned parameters. To perform the coagulation and flocculation process we worked with two types of reagents for the coagulant, which were aluminum sulphate and ferric chloride, both at 1%, so we could evaluate the results of each and see which of the two provided greater efficiency; as for the flocculator, only 1% cationic polymer was used. With the results obtained, it was shown that only by working with a physicochemical process, a significant concentration load of the parameters evaluated were removed, lowering their values to within the ranges of the PML stipulated standards for complete wastewater treatment. Key words: sewage water, industrial effluents, coagulation [water treatment], flocculation, polymers, aluminum sulfate, ferric chloride, sanitation of slaughterhouses.